Color forming developer containing amines



Patented Feb. 20, 1940 Icopold D. Mannes and/Leopold Godowsky, Jr.,

Rochester, N. Y., assignors to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jcrley No Drawing. Application November 12,1938,

Serial lilo. 240,048

3Claims.

This invention relates to color photography and particularly to a method for developing multi-layer film. f V

In certain processes of multi-color photog- 5 raphy, it is necessary to develop simultaneously several emulsion layers carried on one side of the support. In these processes the developer must penetrate all of the layers and develop an image in the innermost layer in about the same o time as that required to'develop an image in the outer layer, as otherwise the outer layer will be over-developed and too dense. A process of this type is described in our prior Patent 2,113,329, granted April 5, 1938. As described therein, a

ll multi-layer film after exposure and reversal is subjected to a color-forming development which produces a blue-green dye and a metallic silver image in each of three superpos emulsion layers. to penetrate the emulsion layers'and develop' an image in each of the layers, and it is desirable for j-the developer to penetrate andformthe image as rapidiy'as possible; 7

It IS, therefore, an objectof the. present in VfiiltlOH-fifl' provide a photographic developer for multil'ayer film having an inc reased rate of penetration 'df'the emulsion layers. A further object is to provide a method 'for developing I colored images in multi-layer in shorter time than was hitherto possible. Other objects will appear from the following description of our invention.

These objects are accomplished by adding. a

primary aliphatic-amine, such as ethylene div amine, to'a color-fanning developer in which a primary aromatic amine, such as diethyl para:

forming developers to produce colored imagesv in thelayersythe developing agent used is a primary, aromatic amino compound, such as para-dimethyl amino aniline, 2-amino-5-diethyl-' amino toluene, or amino phenol. If the three layers of th 'sfilm are to bedeveloped firstto silver and a bhre-green dye, the developing solution may contain a phenolic or naphtholic coupling compound, such as a chlorinated 50. phenol, 2:4 dichloro alpha naphthol or other unsubstituted or substituted naphthol, or a di-- hydroxy naphthol such as 'iz5-dihydron naph thalene. For reasons of, dye stability it is desirable to choose certain couplers in preference 6! to othei's and the phenolic or naphthollc'cou- In this .process the developer is required,

plers are frquently desirable for this reason, although they do not penetrate the emulsion I layers as rapidly as is desired. An alkaline developing solution containing these compounds develops the upper layer with ease, but develops 5 the bottom layer only after an excessively prolonged immersion.

'- We have found that by adding to the coupler developers described above a primary aliphatic amine, such as methylamine, ethylamin or 1 ethylene diamine, the developing time of these developing solutions is considerably decreased and the bottom emulsion layer readily developed. In many cases the aliphatic amines, besides increasing the rate of penetration, have an addi- 15 tional beneficial efiect'in retarding deposition of a general dye fog, thereby improving the character of the dye image. These compounds may also prevent excessive surface development, thereby insuring more even dye formation 20 throughout the thickness of the emulsion layers.

'A suitable formula 'for a rapidly penetrating color-forming developer is as follows, it being I understood that this example'is merely illustrative. 25 2-amino 5-diethy lamino to1uene... grams 2.5 Sodium sulflte- ...e.. do 20 Sodium sulfate d 40 Sodium carbonate ;d0 40 Potassium bromide do 2 Ethylene diamine 7 do 3 Ammonium hydroxide (28% solution) cubic centimeters..- 2

2,14 dichloro-a-naphthol -gram 1 Water to liter ,1 5

The above. develdper; without the ethylene diamine, develops-a multi-layer him of the type described in our prior Patent 2,113,329 in about twenty minutes. Whenthe ethylene diamine is 40 added to the developer, the developing time is decreased to about 12 minutes. -With colorforming developers containing from one to-ilve grams of developing agent liter of developing solution, the amount of ethylene diamine or 4,5

other organic amine may varyfrom aboutone gram to about five grams.- The use of organic amines such as ethylene di-" "amine has previously been. suggested for black and white photographic developers, but as farv as we are aware there has been no previous suggestion ofthe use of these compounds in color developers, particularly color-forming developers of the type containing a primaryaromatic amino developing agent and a coupler' compoundfor is 5 tion are illustrative only and that our invention is to be taken as limited only by the scope of the appended claims.

We claim: 1. A color-forming photographic developer 10 having a rapid rate of penetration for gelatin layers, comprising a primary aromatic amino developing agent, a compound which couples with the oxidation product of the developing agent on photographic development, and a primary 5 aliphatic amine.

2. A color-forming photographic developer .having a rapid rate of penetration for gelatin layers, comprising a primary aromatic amino developing agent, a compound which couples with the oxidation product of the developing agent on photographic development, and ethylene diamine.

3. A color-forming photographic developer having a rapid rate of penetration for gelatin layers comprising a dialkyl amino aniline dey veloping agent, acompound which couples with the oxidation product of the developing agent on photographic development, and ethylene diamine.

LEOPOLD D. MANNES. LEOPOLD GODOWBKY, Jr. 

